In recent years, wearable equipments are becoming popular because they are easy to wear and ready to be used by users at any moment. Nowadays, there are brought about a variety of wearable electronic equipments such as glasses, cap brims, watches etc. Intelligent watches belong to a relatively common type of wearable intelligent equipments. Users can use them to examine and record daily life data, for example, time, exercises, sleep and so on in real time and further synchronize the data with other electronic devices, making their quality of life improved greatly.
However, because the existing intelligent watches focus their functionality on amusements, the carried intelligent watches can not aid in the wearers' self-rescue when the wearers are trapped, especially, in a dark environment.